Data protection techniques make copies of data so that primary data may be restored if the primary data is lost or corrupted due to, for example, hardware failure, software failure, or user error. There are a range of techniques available for data protection. Inter-array mirroring protects against loss of a disk within a disk array. Local backup to tape or disk protects against failure of a primary storage device (e.g., a disk drive or a disk array). Remote mirroring protects against a site failure.
A typical data protection configuration employs a local backup that periodically copies data (e.g., on a daily basis) and a remote mirror that synchronously or asynchronously mirrors primary storage. Generally, the backup data is used to restore data to some state in the past and the remote mirror is used to restore loss of primary storage.